From A Weak to Confident Communicator - 30 Day Challenge
As human beings, you read the emotions and expressions of a person. Some people are naturally good at it while some not quite so. Irrespective of how good you are, you will subconsciously read the facial expressions and body language of people.
At the simplest level, you can sense when a person is happy, angry or sad. Now assume you were the person who was undergoing such emotions. For example, if you were angry, you would expect the other person to calm you down instead of provoking you. If you were happy, you would be pleased to have the other person share your excitement.
When you match the mood of a person in your words, you make a better impression on people. If someone tells you good news, sound excited about it. If someone seems sad, lower your voice and pace to sound sad yourself. Some cases like anger are exceptions because if you match the mood of anger with anger, you will create more damage than good.
Today, you must change your words/tone to match the mood of the other person.